首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The genetic characteristics of all life forms on earth are embodied in the chemical structure of DNA molecules. An organism’s DN
The genetic characteristics of all life forms on earth are embodied in the chemical structure of DNA molecules. An organism’s DN
admin
2010-07-14
42
问题
The genetic characteristics of all life forms on earth are embodied in the chemical structure of DNA molecules. An organism’s DNA molecules provide a complete blueprint for its physical makeup. Genetic engineering is the process of altering the DNA genetic code to change the characteristics of plants and animals. Through the process, scientists can literally build to order new life forms that perform desired functions. For hundreds of years, humans have engineered the development of food crops and domesticated animals through selective breeding practices. For example, the modern dairy cow is the result of centuries of carefully breeding individual animals that carried the genetic trait for high milk production. However, new technology makes it possible for scientists to restructure the DNA molecules themselves and thus obtain more rapid and more radical genetic changes than were possible in the past. This new process is commonly called recombinant DNA technology or gene splicing because it involves disassembling the DNA molecule and then recombining or splicing the pieces according to a new pattern. The gene-spliced DNA molecule may have a genetic code that has never existed before.
Although recombinant DNA technology is still in its infancy, it has al ready demonstrated its value. New crop breeds produced by this process are already growing in farmers’ fields. Crops that are genetically engineered to resist pests, diseases, and drought could be important in efforts to alleviate starvation around the world. Scientists are trying to use genetic engineering to produce important drugs such as insulin (胰岛素) and interferon (干扰素) cheaply. They are also working on a genetically engineered generation of wonder drugs to combat cancer and other killer diseases. However, the recombinant DNA technology brings with it problems our society has not previously faced. Gene splicing could produce new disease microorganisms, deadly to us or to the plants and animals upon which we depend. The possibility of altering human genetic structure raises serious moral, political, and social is sues. Genetic engineering illustrates dramatically the promises and dangers of technological development. The decisions our society makes about genetic engineering will undoubtedly have tremendous consequences in the years to come.
The word "alleviate" (Paragraph 2) is nearest in meaning to ______.
选项
A、relieve
B、avoid
C、eliminate
D、terminate
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/7m7K777K
0
大学英语六级
相关试题推荐
Recentlymoreandmoreattentionhasbeenfocusedtotheproblemofpreservingthe
Tornadoes,whirlwinds,andwatersproutsarerotatingfunnelcloudairmassesofsmalldiameter.Theyaredifferentiatedbythei
Inadditiontohistheoryofcolour,Newtondevelopedatheoryofhowlighttravels.Thisisknownasthecorpuscular(微粒子的)the
A、Moremoney.B、Fairtreatment.C、Acollegeeducation.D、Shorterworkhours.A对话中女性提到男性的老板对他很赏识,正考虑每个月给他多放两天假,但男性的回答是不希望这样,更希望多赚
A、Shewilltakesubway.B、Shewillhurrytotheconference.C、Shewillskiptheconferenceandgosightseeing.D、Shewilltakea
A、Yellow.B、Red.C、Green.D、Black.A本题问“博物馆的屋顶是什么颜色”。文中提到“TheMuseumisyellow,whichstandsfortheemperor"。故[A]“黄色”为正确答案。
A、Noticethewaythepersonistalking.B、Takeagoodlookatthepersontalking.C、Mindhistone,hispostureandthelookinh
Iflifeexpectancywereamarathon,theUnitedStatesisfadingfromthepack.Althougheveryoneislivinglonger,theinhabitan
A、Castles’structureandtheeatinghabitinthem.B、Castles’structureandthepeoplewholivedinthem.C、Castles’structurea
GiantPandaCharacteristicsofGiantPandasThescientificnameofGiantPandaisAiluropodamelanoleuca,whichmeans"cat-f
随机试题
E-procurement,alsoknownase-purchasing,istheprocessofrequisitioningdirectorindirectmaterialsusingtheInternetast
常见于骨干的病变是
患者,男,43岁,右下颌体部膨胀5年,生长缓慢。查:下颌骨畸形,现张口受限,右下磨牙松动脱落,肿物表面见齿痕,颊侧膨隆。X线片示右下颌角部阴影约4cm×5cm大小,可见多房性透光区,边缘呈半月切迹,左下双尖牙牙根呈锯齿状吸收,下颌骨下缘受累。以下哪项可
古典建筑是指()。
以“杠杆租赁”为基础的项目融资模式的特点包括()。
It’snosurprisethatJenniferSenior’sinsightful,provocativemagazinecoverstory,"IloveMyChildren,IHateMyLife,"isa
表演游戏
农业现代化是指把建立在直接经验和手工工具基础上的传统农业转变为以现代先进科学技术、生产手段和管理方法为基础的社会化农业的过程。根据以上定义,下列与农业现代化含义不符的一项是( )。
NewYork,London,Parisandotherbigcitiesareexcitingplacestolivein.Therearemanyinterestingthingstoseeanddo.Yo
InAustralia,reportsaboutAboriginalpeopleoftenmakefordepressingreading.Justafewdaysago,thelatestofficialreport
最新回复
(
0
)